Package com.sun.jdo.api.persistence.support

Interface PersistenceManager

public interface PersistenceManager
PersistenceManager is the primary interface for JDO-aware application components. It is the factory for Query and Transaction instances, and contains methods to manage the life cycle of PersistenceCapable instances.

A PersistenceManager is obtained from the PersistenceManagerFactory (recommended) or by construction.

Version:
0.1
Author:
Craig Russell

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    close()
    A PersistenceManager instance can be used until it is closed.
    Transaction
    currentTransaction()
    There is exactly one Transaction associated with a PersistenceManager.
    void
    deletePersistent(Object pc)
    Delete the persistent instance from the data store.
    void
    deletePersistent(Object[] pcs)
    Delete an array of instances from the data store.
    void
    deletePersistent(Collection pcs)
    Delete a Collection of instances from the data store.
    Collection
    getExtent(Class persistenceCapableClass, boolean subclasses)
    The PersistenceManager may manage a collection of instances in the data store based on the class of the instances.
    Object
    getObjectById(Object oid)
    This method locates a persistent instance in the cache of instances managed by this PersistenceManager.
    Object
    getObjectById(Object oid, boolean validate)
    This method locates a persistent instance in the cache of instances managed by this PersistenceManager.
    Object
    getObjectId(Object pc)
    The ObjectId returned by this method represents the JDO identity of the instance.
    Class
    getObjectIdClass(Class cls)
    In order for the application to construct instance of the ObjectId class it needs to know the class being used by the JDO implementation.
    PersistenceManagerFactory
    getPersistenceManagerFactory()
    This method returns the PersistenceManagerFactory used to create this PersistenceManager.
    Properties
    getProperties()
    The JDO vendor might store certain non-operational properties and make those properties available to applications (for troubleshooting).
    boolean
    getRequireCopyObjectId()
    Returns the boolean value of the requireCopyObjectId flag for this PersistenceManager.
    boolean
    getRequireTrackedSCO()
    Returns the boolean value of the requireTrackedSCO flag for this PersistenceManager.
    boolean
    getSupersedeDeletedInstance()
    Returns the boolean value of the supersedeDeletedInstance flag for this PersistenceManager.
    Object
    getTransactionalInstance(Object pc)
    This method is used to get a PersistenceCapable instance representing the same data store object as the parameter, that is valid for this PersistenceManager.
    Object
    getUserObject()
    The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.
    boolean
    isClosed()
    A PersistenceManager instance can be used until it is closed.
    void
    makePersistent(Object pc)
    Make the transient instance persistent in this PersistenceManager.
    void
    makePersistent(Object[] pcs)
    Make an array of instances persistent.
    void
    makePersistent(Collection pcs)
    Make a Collection of instances persistent.
    Object
    newCollectionInstance(Class type, Object owner, String fieldName, Class elementType, boolean allowNulls, int initialSize)
    Returns a new Collection instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields.
    Query
    newQuery()
    Create a new Query with no elements.
    Query
    newQuery(Class cls)
    Create a new Query specifying the Class of the candidate instances.
    Query
    newQuery(Class cls, String filter)
    Create a new Query with the Class of the candidate instances and Filter.
    Query
    newQuery(Class cls, Collection cln)
    Create a new Query with the Class of the candidate instances and candidate Collection.
    Query
    newQuery(Class cls, Collection cln, String filter)
    Create a new Query with the Class of the candidate instances, candidate Collection, and Filter.
    Query
    newQuery(Object compiled)
    Create a new Query using elements from another Query.
    Object
    newSCOInstance(Class type, Object owner, String fieldName)
    Returns a new Second Class Object instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields.
    void
    setRequireCopyObjectId(boolean flag)
    Sets the requireCopyObjectId flag for this PersistenceManager.
    void
    setRequireTrackedSCO(boolean flag)
    Sets the requireTrackedSCO flag for this PersistenceManager.
    void
    setSupersedeDeletedInstance(boolean flag)
    Sets the supersedeDeletedInstance flag for this PersistenceManager.
    void
    setUserObject(Object o)
    The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.

  • Method Details

    • isClosed

      boolean isClosed()
      A PersistenceManager instance can be used until it is closed.
      Returns:
      if this PersistenceManager has been closed
      See Also:

    • close

      void close()
      A PersistenceManager instance can be used until it is closed.

      This method closes the PersistenceManager, which if pooled, releases it to the pool of available PersistenceManagers.

    • currentTransaction

      Transaction currentTransaction()
      There is exactly one Transaction associated with a PersistenceManager.
      Returns:
      the Transaction associated with this PersistenceManager.

    • newQuery

      Query newQuery()
      Create a new Query with no elements.
      Returns:
      a new Query instance with no elements.

    • newQuery

      Query newQuery(Object compiled)
      Create a new Query using elements from another Query. The other Query must have been created by the same JDO implementation. It might be active in a different PersistenceManager or might have been serialized and restored.
      Parameters:
      compiled - another Query from the same JDO implementation
      Returns:
      the new Query

    • newQuery

      Query newQuery(Class cls)
      Create a new Query specifying the Class of the candidate instances.
      Parameters:
      cls - the Class of the candidate instances
      Returns:
      the new Query

    • newQuery

      Query newQuery(Class cls, Collection cln)
      Create a new Query with the Class of the candidate instances and candidate Collection. specified.
      Parameters:
      cls - the Class of the candidate instances
      cln - the Collection of candidate instances
      Returns:
      the new Query

    • newQuery

      Query newQuery(Class cls, String filter)
      Create a new Query with the Class of the candidate instances and Filter. specified.
      Parameters:
      cls - the Class of the candidate instances
      filter - the Filter for candidate instances
      Returns:
      the new Query

    • newQuery

      Query newQuery(Class cls, Collection cln, String filter)
      Create a new Query with the Class of the candidate instances, candidate Collection, and Filter.
      Parameters:
      cls - the Class of the candidate instances
      cln - the Collection of candidate instances
      filter - the Filter for candidate instances
      Returns:
      the new Query

    • getExtent

      Collection getExtent(Class persistenceCapableClass, boolean subclasses)
      The PersistenceManager may manage a collection of instances in the data store based on the class of the instances. This method returns a Collection of instances in the data store that might be iterated or given to a Query as the Collection of candidate instances.
      Parameters:
      persistenceCapableClass - Class of instances
      subclasses - whether to include instances of subclasses
      Returns:
      a Collection of instances
      See Also:

    • getObjectById

      Object getObjectById(Object oid)
      This method locates a persistent instance in the cache of instances managed by this PersistenceManager. If an instance with the same ObjectId is found it is returned. Otherwise, a new instance is created and associated with the ObjectId.

      If the instance does not exist in the data store, then this method will not fail. However, a request to access fields of the instance will throw an exception.

      Parameters:
      oid - an ObjectId
      Returns:
      the PersistenceCapable instance with the specified ObjectId

    • getObjectId

      Object getObjectId(Object pc)
      The ObjectId returned by this method represents the JDO identity of the instance. The ObjectId is a copy (clone) of the internal state of the instance, and changing it does not affect the JDO identity of the instance.
      Parameters:
      pc - the PersistenceCapable instance
      Returns:
      the ObjectId of the instance

    • getTransactionalInstance

      Object getTransactionalInstance(Object pc)
      This method is used to get a PersistenceCapable instance representing the same data store object as the parameter, that is valid for this PersistenceManager.
      Parameters:
      pc - a PersistenceCapable instance
      Returns:
      the PersistenceCapable instance representing the same data store object

    • makePersistent

      void makePersistent(Object pc)
      Make the transient instance persistent in this PersistenceManager. This method must be called in an active transaction. The PersistenceManager assigns an ObjectId to the instance and transitions it to persistent-new. The instance will be managed in the Extent associated with its Class. The instance will be put into the data store at commit.
      Parameters:
      pc - a transient instance of a Class that implements PersistenceCapable

    • makePersistent

      void makePersistent(Object[] pcs)
      Make an array of instances persistent.
      Parameters:
      pcs - an array of transient instances
      See Also:

    • makePersistent

      void makePersistent(Collection pcs)
      Make a Collection of instances persistent.
      Parameters:
      pcs - a Collection of transient instances
      See Also:

    • deletePersistent

      void deletePersistent(Object pc)
      Delete the persistent instance from the data store. This method must be called in an active transaction. The data store object will be removed at commit. Unlike makePersistent, which makes the closure of the instance persistent, the closure of the instance is not deleted from the data store. This method has no effect if the instance is already deleted in the current transaction. This method throws an exception if the instance is transient or is managed by another PersistenceManager.
      Parameters:
      pc - a persistent instance

    • deletePersistent

      void deletePersistent(Object[] pcs)
      Delete an array of instances from the data store.
      Parameters:
      pcs - a Collection of persistent instances
      See Also:

    • deletePersistent

      void deletePersistent(Collection pcs)
      Delete a Collection of instances from the data store.
      Parameters:
      pcs - a Collection of persistent instances
      See Also:

    • getPersistenceManagerFactory

      PersistenceManagerFactory getPersistenceManagerFactory()
      This method returns the PersistenceManagerFactory used to create this PersistenceManager. It returns null if this instance was created via a constructor.
      Returns:
      the PersistenceManagerFactory that created this PersistenceManager

    • setUserObject

      void setUserObject(Object o)
      The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.
      Parameters:
      o - the user instance to be remembered by the PersistenceManager
      See Also:

    • getUserObject

      Object getUserObject()
      The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.
      Returns:
      the user object associated with this PersistenceManager
      See Also:

    • getProperties

      Properties getProperties()
      The JDO vendor might store certain non-operational properties and make those properties available to applications (for troubleshooting).

      Standard properties include:

    • VendorName
    • VersionNumber
      • Returns:
      the Properties of this PersistenceManager

    • getObjectIdClass

      Class getObjectIdClass(Class cls)
      In order for the application to construct instance of the ObjectId class it needs to know the class being used by the JDO implementation.
      Parameters:
      cls - the PersistenceCapable Class
      Returns:
      the Class of the ObjectId of the parameter

    • newSCOInstance

      Object newSCOInstance(Class type, Object owner, String fieldName)
      Returns a new Second Class Object instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields. If a collection class is created, then the class does not restrict the element types, and allows nulls to be added as elements.
      Parameters:
      type - Class of the new SCO instance
      owner - the owner to notify upon changes
      fieldName - the field to notify upon changes
      Returns:
      the object of the class type

    • newCollectionInstance

      Object newCollectionInstance(Class type, Object owner, String fieldName, Class elementType, boolean allowNulls, int initialSize)
      Returns a new Collection instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields. The collection class restricts the element types allowed to the elementType or instances assignable to the elementType, and allows nulls to be added as elements based on the setting of allowNulls. The Collection has an initial size as specified by the initialSize parameter.
      Parameters:
      type - Class of the new SCO instance
      owner - the owner to notify upon changes
      fieldName - the field to notify upon changes
      elementType - the element types allowed
      allowNulls - true if allowed
      initialSize - initial size of the Collection
      Returns:
      the object of the class type

    • getObjectById

      Object getObjectById(Object oid, boolean validate)
      This method locates a persistent instance in the cache of instances managed by this PersistenceManager. The getObjectById method attempts to find an instance in the cache with the specified JDO identity. The oid parameter object might have been returned by an earlier call to getObjectId or might have been constructed by the application.

      If the PersistenceManager is unable to resolve the oid parameter to an ObjectId instance, then it throws a JDOUserException.

      If the validate flag is false, and there is already an instance in the cache with the same JDO identity as the oid parameter, then this method returns it. There is no change made to the state of the returned instance.

      If there is not an instance already in the cache with the same JDO identity as the oid parameter, then this method creates an instance with the specified JDO identity and returns it. If there is no transaction in progress, the returned instance will be hollow or persistent-nontransactional, at the choice of the implementation.

      If there is a transaction in progress, the returned instance will be hollow, persistent-nontransactional, or persistent-clean, at the choice of the implementation.

      It is an implementation decision whether to access the data store, if required to determine the exact class. This will be the case of inheritance, where multiple PersistenceCapable classes share the same ObjectId class.

      If the validate flag is false, and the instance does not exist in the data store, then this method might not fail. It is an implementation choice whether to fail immediately with a JDODataStoreException. But a subsequent access of the fields of the instance will throw a JDODataStoreException if the instance does not exist at that time. Further, if a relationship is established to this instance, then the transaction in which the association was made will fail.

      If the validate flag is true, and there is already a transactional instance in the cache with the same JDO identity as the oid parameter, then this method returns it. There is no change made to the state of the returned instance.

      If there is an instance already in the cache with the same JDO identity as the oid parameter, but the instance is not transactional, then it must be verified in the data store. If the instance does not exist in the datastore, then a JDODataStoreException is thrown.

      If there is not an instance already in the cache with the same JDO identity as the oid parameter, then this method creates an instance with the specified JDO identity, verifies that it exists in the data store, and returns it. If there is no transaction in progress, the returned instance will be hollow or persistent-nontransactional, at the choice of the implementation.

      If there is a data store transaction in progress, the returned instance will be persistent-clean. If there is an optimistic transaction in progress, the returned instance will be persistent-nontransactional.

      Parameters:
      oid - an ObjectId
      validate - if the existence of the instance is to be validated
      Returns:
      the PersistenceCapable instance with the specified ObjectId
      See Also:

    • getSupersedeDeletedInstance

      boolean getSupersedeDeletedInstance()
      Returns the boolean value of the supersedeDeletedInstance flag for this PersistenceManager. If set to true, deleted instances are allowed to be replaced with persistent-new instances with the equal Object Id.
      Returns:
      boolean supersedeDeletedInstance flag

    • setSupersedeDeletedInstance

      void setSupersedeDeletedInstance(boolean flag)
      Sets the supersedeDeletedInstance flag for this PersistenceManager.
      Parameters:
      flag - boolean supersedeDeletedInstance flag

    • getRequireCopyObjectId

      boolean getRequireCopyObjectId()
      Returns the boolean value of the requireCopyObjectId flag for this PersistenceManager. If set to false, the PersistenceManager does not create a copy of an ObjectId for PersistenceManager.getObjectId(Object pc) and PersistenceManager.getObjectById(Object oid) requests.
      Returns:
      boolean requireCopyObjectId flag
      See Also:

    • setRequireCopyObjectId

      void setRequireCopyObjectId(boolean flag)
      Sets the requireCopyObjectId flag for this PersistenceManager. If set to false, the PersistenceManager will not create a copy of an ObjectId for PersistenceManager.getObjectId(Object pc) and PersistenceManager.getObjectById(Object oid) requests.
      Parameters:
      flag - boolean requireCopyObjectId flag
      See Also:

    • getRequireTrackedSCO

      boolean getRequireTrackedSCO()
      Returns the boolean value of the requireTrackedSCO flag for this PersistenceManager. If set to false, the PersistenceManager will not create tracked SCO instances for new persistent instances at commit with retainValues set to true and while retrieving data from a datastore.
      Returns:
      boolean requireTrackedSCO flag

    • setRequireTrackedSCO

      void setRequireTrackedSCO(boolean flag)
      Sets the requireTrackedSCO flag for this PersistenceManager. If set to false, the PersistenceManager will not create tracked SCO instances for new persistent instances at commit with retainValues set to true and while retrieving data from a datastore.
      Parameters:
      flag - boolean requireTrackedSCO flag